[PATCH v2 0/2] scpi-sensors: Fix SCP sensor readings scale

Guenter Roeck linux at roeck-us.net
Wed Mar 8 11:11:33 PST 2017


On Wed, Mar 08, 2017 at 09:24:38AM +0100, Carlo Caione wrote:
> On Fri, Mar 3, 2017 at 10:14 AM, Carlo Caione <carlo at caione.org> wrote:
> > From: Carlo Caione <carlo at endlessm.com>
> >
> > The implementation details for SCPI seems to suggest that the sensor
> > readings must be reported by SCP using a well defined scale
> > (millidegree Celsius for temperature, millivolts for voltage,
> > milliamperes for current, microwatts for power and microjoules for
> > energy).
> >
> > This is also important for the interaction with other subsystems: for
> > example both the thermal sub-system and the hwmon sysfs interface expect
> > the temperature expressed in millidegree Celsius.
> >
> > Unfortunately since this behaviour is dependent on the firmware
> > implementation there are cases where the sensor readings are reported
> > using a different scale. For example in the Amlogic SoCs the
> > temperature is reported in degree and not millidegree Celsius.
> >
> > In this patchset we introduce a new DT property `scpi,sensors-scale` that is
> > used by the scpi-hwmon driver to convert the sensor readings to the expected
> > scale.
> >
> > v2:
> >  - Added data validation (scale != 0)
> >  - s/unsigned int/u32/ for the array
> >  - Switched to array initialiser notation
> >  - Introduced scpi_scale_reading()
> 
> gentle ping
> 

Waiting for Rob to provide feedback on the devicetree property.

Guenter



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